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Evolution Confusion

There is a very common hang-up people have about evolution. They understand that the theory says that current organisms are descended from earlier organisms, but cannot process the fact that these ancestors can look so completely different. To make my point, first try fulling accepting this fact:

That’s a hard one for most people to come to terms with, as it is so far removed from our ideas about ancestry.

But whether you like it or not, it’s true. Skirting this ancestry, and the implications of evolution in general, produces the common misconception that there is some “transitional species” between each recognizable species we see today. Of course there are ancestors that are genetically, morphologically, physiologically, transitional between species; a species of feathered dinosaur is physiologically transitional between dinosaurs and birds, for example, but this is not what the misconception is. Many people don’t agree with the fact of evolution because they think it impossible that species alive today are descended from earlier (very different) species.

Rather than follow the science that clears up the issue, evolution deniers like Creationists use the misconception and make two mistakes about the progression of life: first they assume that every species that is alive today has always been alive, so their ideas about what should be transitional to what is clearly warped. Second, they imagine the tree of life to look like a straight line, with bacteria morphing all the way to humans in an upward progression of complexity.

Assuming that every animal species alive today is the only species to ever exist is just plain ignorance, just go to a museum and look at the fossils for proof. Furthermore, assigning humans a special place at the top of Mount Evolution is misinformed and unwarranted. Evolution does not have a will, nor does it select for higher complexities of life, it only selects what works. It may be hard to wrap you head around, but a sea slug is more evolved than you are.

Creationist-like ideas about ancestry, stemming from the mistake that the only species that exist are the ones alive now, are highlighted by the picture below:

Kirk Cameron’s now infamous “Crocoduck”

This confusion of different ancestral lines cannot be reconciled other than to say that it is a false argument. No biologist, biology textbook, etc., has ever said that evolution works this way. It arises from plain ignorance of the theory.

A (very) rough idea of how evolution has progressed looks something like this:

In this picture you can see the common ancestral lines between organisms. Given these proven lines, you can see how ridiculous it is to suppose that there should be something like a “Crocoduck”.–Click to enlarge

If you wish to join me for a bit of science, this evolution confusion can be reconciled.

A gradual change

Many creationists often demand a “missing link” between apes and humans. However, between apes and humans, there was no distinguishable “missing link” that was half-human-half-ancestor, as I believe the creationists require. This is not how evolution works. Small changes, caused by random mutations, the beneficial of those mutations being passed on to subsequent generations, altered the species gradually, over millions of years until Homo sapiens was distinguishable.

Let me give you an example:

You can barely tell the visual or genetic differences between a mother and her daughter. Both are remarkably similar, but with small changes appearing in the daughter due to the random assortment of genetic mutations. Now consider a mother-daughter chain, with each mother standing next to her daughter, with that daughter being a mother to the next, etc. At any single point along the mother-daughter chain, there will not be a daughter standing next to her mother who is a different species. But if you compare the beginning of the chain to the end of it, you can see there have been subtle changes over the generations. With a long enough chain, over thousands or millions of years guided by evolution, these small changes can accumulate and become big changes.

For an even better example, read the text in the graphic below, paying special attention to the color of the text.

Click to enlarge

And it’s just that simple. It’s elegant, it’s logical, and, most importantly, it is backed up by numerous lines of evidence and has eluded disproof for over almost 200 years (certainly not from lack of trying). It is the best explanation we have to explain the diversity of life.

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15 thoughts on “Evolution Confusion”

This is very well presented, Kyle.
I particularly like your text color analogy which, one would hope, should make the point clear to at least the less committed creationists.

In the evolutionary context, however, I would be most interested to hear your reaction to the wider model that I present in “The Goldilocks Effect: What Has Serendipity Ever Done For Us?”, a free download in e-book formats from the “Unusual Perspectives” website.
It is quite short and very informal but should give the gist to anyone who is prepared to step outside our naturally anthropocentric mindset.

“Conditions around the deep sea vents with their associated strong energy gradients provide other alternatives. The Alkaline vent hypothesis, with its additional appeal of suggesting a plausible origin of the cell (another unsolved mystery) is particularly attractive.

Nicole, you could check out Nick Lane’s popular book “Life Ascending”, which should give you an insight into such ideas. It will most likely be in your local library and is an easy read”

Horror of horrors – now I am “plugging” even other books of relevance, and, i must admit, am in the habit of doing so. But must refrain from on YOUR site, of course.

I’m a creationist and I am taking no offense. But that last bit was confusing…. I do believe things change. If we say Noah’s ark is real then change has to happen! I mean we have Africans, native Americans and Japanese. The daughter/mother thing makes scene… But I find it a little weird to think that the daughters would start growing antennas or a tail or whatever. You know what I mean? could you explain?

We can use the evolution of the eye as an example. Due to random genetic mutations that appear (due to slightly inaccurate DNA copying) each time an organism reproduces, suppose that an organism develops a few light-sensitive cells (just a few, and not a fully formed “eye”). At first, these few cells would only be able to detect the presence of light or not, but this may help the organism with food gathering or defense, and therefore it will pass on its genes more often than others of its species without those cells. Over time, as more and more of the organisms with light-sensitive cells reproduce and pass on the genes that make those cells, those genes become more prevalent in the population of organisms.

Now, suppose that another random genetic mutation in that population develops a slight concave structure to those light-sensitive cells, now allowing the organism to tell whether there is light or not and what direction it is coming from. Again, because this may be very beneficial for the organism, those organisms with this trait will pass on their genes more often than those that do not. This is natural selection.

Over hundreds of thousands of years, if every beneficial mutation that aids sight is selected for, then you get something like the human eye. In fact, science estimates that the eye evolved in many different animals independently (presumably because the development of light-sensitive cells was so beneficial to them) and in as little as 250,000 years!

Here is a video that hopefully helps describe the process that I outlined above and shows the complete evolution of eye complexity, step-by-step.

That makes a little more sense. But how did live start? You know like, people will talk about how the world was just an asteroid with a little bit of gravity and smaller astreroids will get pulled on the bigger astreroid and soon it is big enough for to be a planet. But how did life start on the planet? Where did the first living organism come from?

And I watched this documentary on dinosaurs called “Dinosaurs or Dragons”. It talked about the evidence that dinosaurs and people lived at the same time. And there was a lot of evidence! You should watch it. I’d like to hear….. to read your comments on it. If you don’t have the time or don’t want to it’s okay! I just wanted to hear an evolutionist’s opinion on that movie.

Science does not have an exact theory of how life on Earth started (like we do for how the diversity of life that we see arose). However, we do have a number of plausible hypotheses. First, the earth may have been seeded with bacteria from an ancient Mars. This idea has life arising on Mars, Mars being impacted by a major asteroid, and that asteroid carrying hardy, space-surviving bacteria to earth. This idea is called panspermia.

But the most mainstream view of how life first came about would be the “primordial soup” you often hear about. As earth formed, the oceans on the early earth were saturated with various molecules and organic compounds. Given enough time, these molecules combine and interact and eventually give rise to a molecule that can self-replicate, given the interactions of its chemistry. Once we have molecules that can produce copies of itself, we quickly encounter something like DNA, evolution can take hold, and life begins to arise. I should note that we have preliminary evidence of this being possible in the lab.

I have not seen the movie you refer to, but I can assure you that the premise (that humans and dinosaurs coexisted) is completely false. Every single line of evidence says otherwise. The age of human and dinosaur fossils, for example, put us hundreds of millions of years apart. When we look at genetic evidence, as another example, we find that modern humans have only been around for about 200,000 years. Again, this is millions of years after dinosaurs died out (65 million years ago). As far as science is concerned, there is not one piece of evidence that has passed scrutiny that suggests that humans lived with dinosaurs. I would like to hear what evidence there is supposedly to the contrary.

Adsorption, or evaporative concentration on shores and ponds, together with solar radiation to provide the energy gradient provide one set of plausible mechanisms.

Conditions around the deep sea vents with their associated strong energy gradients provide other alternatives. The Alkaline vent hypothesis, with its additional appeal of suggesting a plausible origin of the cell (another unsolved mystery) is particularly attractive.

Nicole, you could check out Nick Lane’s popular book “Life Ascending”, which should give you an insight into such ideas. It will most likely be in your local library and is an easy read.

I’ve been learning about cells and they’re extremely complicated! I find it hard to believe an eye came from a couple of light sensitive cells. And you can’t tell me all the evidence in Dinosaurs or Dragons is false. You have no idea if it is or not! you haven’t even watched it!

This I saw on T.V. I don’t like how the guy presents it, I don’t like all the jabs at evolutionists. But he’s got a point! how did the giraffes know to put a sponge under their brain? how did they know to put the rest of the stuff that helps them survive? What are the chances that all that stuff randomly forming over time?

I know it might be hard for you to believe, but the video I provided you with in the last exchange we had actually went through all of the intermediary steps between light sensitive cells and a fully formed eye. Science isn’t just guessing about this, we have examples of the intervening stages in the fossil record and in living creatures today. In fact, the evolution of the eye is quite well established.

Though I have not watched your creationist video, I can with assurance say that there is not one single piece of scientific evidence that would indicate that humans and dinosaurs lived together. Again, if you have a particular example that you would like to discuss, please let me know and I can try to answer it for you.

Nicole, I think you are misunderstanding how evolution works. No organism “knows” what it needs to survive. Organisms are surviving and adapting, but it is not like they need to evolve a certain part or they will die out. As a population lives, it passes on its genes, and those genes will mutate, thereby giving rise to adaptations (some beneficial, some not). The ones that are beneficial will be naturally selected because it helps the population pass on their genes, nothing more. A giraffe didn’t “need” a pressure-reducing “sponge” in its brain; a mutation was selected for early on in the history of the giraffe species that allowed it to better withstand its own blood pressures, and therefore those genes were passed on. The development of the sponge would be a very slow and incremental process, not all at once. But in the end, with small mutations being selected for, we end up with something like we see today. However, at no point did the giraffe “need” the sponge, the mutation simply helped it pass on its genes, and its ancestors survived without it.

Evolution does not have a will. It only selects the beneficial mutations that are thrown up in every population. Those organisms with beneficial mutations will pass on their genes more often than those organisms that do not have those mutations. There is no “need,” only mutation and selection based on the survival of a species.

Lastly, I can not stress this enough: evolution is not random. The mutations that arise from DNA recombination are random, yes, but natural selection (which drives evolution) is not random. Keep in mind that evolution works in very small steps over millions of years. It is easy for you to say that “it is too improbable to evolve an eye,” but you are assuming this all happens at once and by chance. If you look at how evolution actually operates, each tiny step from a simple to a complex biological component is very plausible. Small DNA mutations happen with every new fertilized egg (for example, you most likely have a few mutations in your DNA which differ from your mother and father). If we follow this path for a few million years, we end up with something complex. Nicole, you are only looking at the end points of this evolutionary timeline. You cannot just look at the beginning and the end and say it is impossible because they are so different. Because if we follow all the small, likely, naturally selected steps along the way, over millions of years, it becomes obvious how simplicity begets complexity. Again, I should note that we have numerous examples of these intermediary steps (in the fossil record and from genetic evidence).

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About the Author

Kyle Hill is a science writer and communicator who specializes in finding the secret science in your favorite fandom. His work has appeared in Wired, The Boston Globe, Scientific American, Popular Science, Discover Magazine, and more. He is a TV correspondent for Al Jazeera America's science and technology show TechKnow.